From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Camshaft comparison tests for full and moderate supercharged engines, including valve timing data.
| Identifier | ExFiles\Box 33\4\ Scan128 | |
| Date | 3rd January 1929 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/VH. c. to BJ. SG.{Arthur F. Sidgreaves - MD} c. to Mor. RG.{Mr Rowledge} c. to E.{Mr Elliott - Chief Engineer} BY.{R.W. Bailey - Chief Engineer} X1770 Hs{Lord Ernest Hives - Chair}/VH1/LG3.1.29. CAMSHAFT COMPARISON TESTS - X1770 / 49003 ON (1) Full supercharged engine. (2) Moderate supercharged engine. Tests have been completed (and officially observed by the A.I.D.) which shew the gain obtained by the use of long duration camshafts on S/C. engines. We give herewith the curves obtained for :- (1) Full S/C. engines. Comparative power curves at 10,500 ft. (2) M.{Mr Moon / Mr Moore} S/C. engines. Comparative power curves at 4000 ft. All these curves take the form of officially recognised comparisons and together with the results obtained on a normal 7/1 comp: engine (Hs{Lord Ernest Hives - Chair}2/LG16.10.26) justify the fitting of long duration camshafts to all F.{Mr Friese} engines in service. We give herewith the original std. valve timing compared with the timing for long duration camshafts :- Tappet clearance .030" Point on cycle. Std. Camshafts. Long Duration Camshafts. Inlet opens 8° A.T.D.C. 11° B.T.D.C. Inlet closes 38° A.B.D.C. 40° A.B.D.C. Exhaust opens 30° B.B.D.C. 48° B.B.D.C. Exhaust closes 8° A.T.D.C. 1° A.T.D.C. Hs{Lord Ernest Hives - Chair}/V.Halliwell. | ||